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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

The system dynamics approach as a modelling tool for health care

Nienaber, Petrus Millar 06 June 2013 (has links)
In this dissertation System Dynamics is used as a modelling approach to model health care systems to gain a better understanding of the system’s behaviour. This improved understanding can be used to better manage the system and in turn will translate to improved health outcomes. The characteristics of complex systems were reviewed to define a health system as a complex system. Four appropriate modelling approaches was studied that could be used to model complex systems. These modelling approaches included: Monte Carlo Simulation, Discrete Event Simulation, System Dynamics and Agent Based Modelling. System Dynamics was identified as being the most appropriate modelling methodology to be used for the framework. Before the framework was developed health system performance measurement was reviewed to further the understanding of health system measurement. The framework was developed according to the insights gained from the previous reviews. Specifically the elements identification was customised to the health care environment based on available health indicators. The framework was applied in a case study where a section of the South Africa health care system was modelled to focus interventions for human immunodeficiency virus (HIV). The outcomes of the case studies delivered an increased understanding of the system behaviour and also showed appropriates of the framework. / Dissertation (MEng)--University of Pretoria, 2012. / Industrial and Systems Engineering / unrestricted
32

Life performance assessment methodologies for combined solar energy technologies : a case study on system parts in nordic climates

Stojanovic, Bojan January 2007 (has links)
The main questions concerning energy technologies today are their economical and environmental impacts. These entities are (at the present) assessed on the basis that operations proceed as newly installed/designed systems, during an assumed working life period. While this is the common way of perceiving energy systems, performance-over-time will change as an effect of (e.g. material) degradation and not solely of different operation scenarios. How and to what extent, is the question that needs assessing in order to evaluate if these changes will jeopardise the intended system performance requirement. In turn, this pro-active assessment and analysis is in line with today’s performance based directives, laws, regulations and concepts; of which the working life is an essential part. The main context of the thesis, is a contribution to the Research and Development (R&D) topic on life performance of energy technologies, with papers on a literature review and case study on two system parts: solar collector and ground heat exchanger (borehole); within the energy technology area of combined solar energy technologies/systems utilised in buildings. The thesis specifically presents a general description of requirements on constructed works and their material, components and systems. It also gives an insight to the energy technology R&D and engineering sector, regarding durability and service life assessment methodologies; and also to the durability of constructed works sector, regarding the needs for assessing material degradation in relation to system performance. The case studies presented in the thesis, show how durability of energy technologies may be sought-after, as well as specific knowledge and useful tools, methodologies and test setups for assessing long-term performance of combined solar energy technologies (in this case a solar-assisted heat pump system utilising a building integrated Unglazed Solar Collector and energy storage). The utilisation of solar collectors and heat pumps (primarily for space and domestic tap water heating) has rapidly increased in Sweden during the last decades. Sweden has today the largest heat pump market in Europe. During recent years, there has also been an increased interest in heating systems that combine heat pumps with solar collectors (glazed and unglazed) and energy storages; with the aim of attaining a system that provides higher energy and greater economical performances than individual solar collector or heat pump systems. If these systems are to be successful they must be economically feasible; placing emphasis on the cost, durability and performance of the system. The main issue on life performance of energy technologies is how and to what extent, performance reduction in individual materials and components influences the overall system performance; as the essence of energy system sustainability is system performance. / QC 20101117
33

Brake system simulation to predict brake pedal feel in a passenger car

Day, Andrew J., Ho, Hon Ping, Hussain, Khalid, Johnstone, A. January 2009 (has links)
No / Braking system characteristics, brake system performance and brake system component design parameters that influence brake pedal ‘feel’ in a passenger car have been studied using the simulation modelling package AMESim, in particular to model the linear and nonlinear characteristics of internal components. A passenger car hydraulic brake system simulation model incorporating the brake pedal, booster, master cylinder, brake lines and calipers has been developed to predict brake system response to assist in the design of braking systems with the desired brake pedal force / travel characteristic characteristics to create good brake pedal ‘feel’. This has highlighted the importance of system components, in particular the master cylinder and caliper seal deformation, and the operating characteristics of the booster in determining the brake pedal force / travel characteristic. The potential contribution of these 3 components to brake pedal ‘feel’ improvement has been investigated, and the results of the AMESim model have been verified using experimental measurement data. The model can be used in the future to provide an accurate prediction of brake system response at the design stage thereby saving time and cost.
34

The Influence of Braking System Component Design Parameters on Pedal Force and Displacement Characteristics. Simulation of a passenger car brake system, focusing on the prediction of brake pedal force and displacement based on the system components and their design characteristics.

Ho, Hon Ping January 2009 (has links)
This thesis presents an investigation of braking system characteristics, brake system performance and brake system component design parameters that influence brake pedal force / displacement characteristics as ‘felt’ by the driver in a passenger car. It includes detailed studies of individual brake system component design parameters, operation, and the linear and nonlinear characteristics of internal components through experimental study and simulation modelling. The prediction of brake pedal ‘feel’ in brake system simulation has been achieved using the simulation modelling package AMESim. Each individual brake system component was modelled individually before combining them into the whole brake system in order to identify the parameters and the internal components characteristics that influence the brake pedal ‘feel’. The simulation predictions were validated by experimentally measured data and demonstrated the accuracy of simulation modelling. Axisymmetric Finite Element Analysis (using the ABAQUS software) was used to predict the behaviour of nonlinear elastomeric internal components such as the piston seal and the booster reaction disc which was then included in the AMESim simulation model. The seal model FEA highlighted the effects of master cylinder and caliper seal deformation on the brake pedal ‘feel’. The characteristics of the brake booster reaction disc were predicted by the FEA and AMESim simulation modelling and these results highlighted the importance of the nonlinear material characteristics, and their potential contribution to brake pedal ‘feel’ improvement. A full brake system simulation model was designed, prepared, and used to predict brake system performance and to design a system with better brake pedal ‘feel’. Each of the brake system component design parameters was validated to ensure that the braking system performance was accurately predicted. The critical parameter of brake booster air valve spring stiffness was identified to improve the brake ‘pedal ‘feel’. This research has contributed to the advancement of automotive engineering by providing a method for brake system engineers to design a braking system with improved pedal ‘feel’. The simulation model can be used in the future to provide an accurate prediction of brake system performance at the design stage thereby saving time and cost.
35

Metrics for Evaluating System Level Change in Adolescent and Young Adult (AYA) Cancer Care in Canada / METRICS FOR AYA CANCER CARE IN CANADA

Rae, Charlene January 2021 (has links)
Adolescents and young adults (AYAs, 15-39 years of age) with cancer face unique challenges. Efforts have been made to improve both care and outcomes for this population. Metrics to evaluate AYA cancer care efforts help to ensure that objectives and outcomes are being met. This thesis comprises 7 papers which explore system performance metrics for cancer care and control in AYAs. A scoping review introduces the topic and addresses the current state of indicator metrics for the AYA cancer population. The second paper extends this work and develops a consensus-based list of relevant indicators. The subsequent papers focus on further development of two of the identified indicators for implementation in Canada (identification of patient reported outcome measures (PROMS) for assessing distress; a referral indicator for oncofertility care). This thesis describes 14 indicators in 5 care areas. Two identified indicators were further developed to aid in implementation (“Proportion of AYA patients screened for distress with standardized AYA specific tools” and “Proportion of AYA patients who had fertility preservation discussion before treatment”). Criteria from the National Quality Forum (NQF) were used to assess commonly used PROMs for distress. It was found that although all PROMs had acceptable psychometric properties, only the “Impact of Cancer” scale of the CDS-AYA had strong content validity for AYA with cancer. For Oncofertility, the indicator “Proportion of cases attending a fertility consult visit ≤ 30 days from diagnosis of cancer” was recommended for use. Finally, factors associated with attending such a fertility consult were identified. Important factors for both men and women included: age at diagnosis, risk to fertility, year of diagnosis, treatment with radiation or chemotherapy, region of care, income and residential instability. The information presented in this thesis can be applied to national system performance initiatives to identify and implement metrics to monitor and evaluate cancer care in AYA. / Thesis / Doctor of Philosophy (PhD) / A person 15 to 39 years old with cancer will face many challenges. This is a time of life with many changes such as continuing schooling, getting married, starting a career, or starting a family. To make sure that young people with cancer are getting the best care, and that they have the best chance to achieve their goals and contribute to society, we need to measure what is important to this group. These measures can be used to compare hospitals, or changes over time to help make care better. This paper looks at what we already measure in this group, and what patients, researchers and healthcare workers think also should be measured to help provide the best care for these patients. Measures discussed in this paper could be used in programs to monitor the quality of care given to young people with cancer.
36

SMART MANUFACTURING DIAGNOSTIC SYSTEM (SMDS) CREATING AN ASSESSMENT PROCESS FOR SMALL TO MEDIUM SIZE MANUFACTURERS

LE, DAVID 01 July 2004 (has links)
No description available.
37

Analysis and Comparison of System Performance Using Different Modulation Schemes for Long-Haul Optical Systems and Fiber-To-The-Home Passive Optical Networks

Zhu, Xianming 08 1900 (has links)
<p> Analytical expressions for the propagation impairments due to various noise sources in long-haul optical systems and fiber-to-the-home passive optical networks have been obtained. Extensive comparison has been made in this thesis for systems based on different modulation formats, and the advantage of one over the other is clearly stated.</p> <p> For long-haul fiber optical communication systems with inline amplifiers, we have studied the statistical properties of various noise sources in systems based on differential phase-shift keying (DPSK) such as the linear phase noise induced by the amplifier spontaneous emission (ASE) noise, the intra-channel four-wave mixing (IFWM) and the nonlinear phase noise induced by the interplay between ASE noise and fiber Kerr nonlinearity. The error probability of the system based on DPSK is evaluated semi-analytically. In addition, the error probability of the system based on on-off keying (OOK) is calculated taking into account the effects of ASE noise, and the intra-channel nonlinearities such as IFWM and intra-channel cross-phase modulation (IXPM). Comparison of the performance of systems based on DPSK and OOK is made thereafter.</p> <p> For fiber-to-the-home passive optical networks without inline active photonic devices, different modulation formats have been examined for the downstream and upstream data to enable full-duplex transmission. The statistical properties of Rayleigh backscattering in single-source bi-directional optical systems have been studied including the effects of the high speed external modulation signal and the laser phase noise for systems based on DPSK and OOK. The error probabilities for systems using OOK/OOK topology and DPSK/OOK topology for downstream/upstream transmission have been evaluated and compared.</p> <p> In addition, the interplay of the amplifier spontaneous emission noise, fiber nonlinearity and dispersion has been examined starting from the nonlinear Schrödinger equation on the receiver current fluctuation. The variance of the current noise has been evaluated analytically using the two dimensional perturbation theory.</p> / Thesis / Master of Applied Science (MASc)
38

Implementation and Analysis of Wireless Local Area Networks for High-Mobility Telematics

Aziz, Farhan Muhammad 26 June 2003 (has links)
Wireless networks provide communications to fixed, portable and mobile users and offer substantial flexibility to both end-users and service providers. Current cellular/PCS networks do not offer cost effective high data rate services for applications, such as, telematics, traffic surveillance and rescue operations. This research studies the feasibility and behavior of outdoor implementation of low-cost wireless LANs used for high mobility telematics and traffic surveillance. A multi-hop experimental wireless data network is designed and tested for this purpose. Outdoor field measurements show the wireless coverage and throughput patterns for static and mobile users. The results suggest that multi-hop wireless LANs can be used for high mobility applications if some protocols are improved. / Master of Science
39

GLI STRUMENTI DEL MANAGEMENT IN SANITA': L'IMPATTO DEL SISTEMA DI CONTABILITA' ANALITICA SULLE PERFORMANCE

GRAPS, CHIARA 11 March 2016 (has links)
Nel mondo delle imprese, l’efficacia del sistema di contabilità analitica per il miglioramento delle performance organizzative è ampiamente dimostrata. I risultati della letteratura del settore pubblico sulla relazione diretta tra MAS e performance sono invece ancora scarsi e controversi. La presente ricerca si propone di colmare questo gap e di indagare, con metodo quantitativo, se la presenza di questo strumento nelle aziende sanitarie pubbliche implichi effettivamente una buona performance, misurata sulla base di indicatori, sia economico-finanziari, sia non economico-finanziari. In particolare, lo studio di propone di verificare se le caratteristiche di base di un sistema di management accounting abbiano un significativo impatto positivo sulle performance economico - finanziarie e sull’efficienza e appropriatezza dell’organizzazione; un sistema di contabilità analitica più sviluppato migliori significativamente i risultati economico - finanziari, l’efficienza e l’appropriatezza dell’organizzazione; il livello di sviluppo del MAS comporti un differente impatto sulle performance in funzione di alcune caratteristiche delle organizzazioni sanitarie pubbliche, come l’appartenenza o meno della azienda ad una regione sottoposta ad un piano di rientro dal deficit finanziario, o il fatto di essere o meno una ASL piuttosto che un’Azienda ospedaliera, o di avere una casistica particolarmente complessa. / Management accounting theory has generally assumed that accounting information improves decision-making and, thereby, organizational outcomes. The Italian Legislative Decree no. 502/92 introduced the Management accounting systems in the public health care organizations, within the New Public Management reforms. According to NPM theories, “Management is management” in public and private sectors, so the use of private sector management tools can improve public sector performance. However, “no prior studies have systematically tested whether the same kind of management principles and techniques have the same effects in both public and private organizations” (Hvidman, Andersen, 2013). Indeed, concerning impacts, management accounting research is still mainly focused on manufacturing firms while public sector is largely unexplored. In response to this gap, this study investigates the impact of MAS on financial and non-financial organizational performance of a large sample of health care organizations. More specifically, the purpose of this work is to verify whether: 1) The presence of MAS has positive effects on financial performance, on efficiency and appropriateness; 2) The functionality of the costing system is positively correlated with financial and non-financial organizational performance; 3) The relationship between MAS and organizational performance will be more likely in the presence of some contextual factors.
40

The influence of braking system component design parameters on pedal force and displacement characteristics : simulation of a passenger car brake system, focusing on the prediction of brake pedal force and displacement based on the system components and their design characteristics

Ho, Hon Ping January 2009 (has links)
This thesis presents an investigation of braking system characteristics, brake system performance and brake system component design parameters that influence brake pedal force / displacement characteristics as ‘felt’ by the driver in a passenger car. It includes detailed studies of individual brake system component design parameters, operation, and the linear and nonlinear characteristics of internal components through experimental study and simulation modelling. The prediction of brake pedal ‘feel’ in brake system simulation has been achieved using the simulation modelling package AMESim. Each individual brake system component was modelled individually before combining them into the whole brake system in order to identify the parameters and the internal components characteristics that influence the brake pedal ‘feel’. The simulation predictions were validated by experimentally measured data and demonstrated the accuracy of simulation modelling. Axisymmetric Finite Element Analysis (using the ABAQUS software) was used to predict the behaviour of nonlinear elastomeric internal components such as the piston seal and the booster reaction disc which was then included in the AMESim simulation model. The seal model FEA highlighted the effects of master cylinder and caliper seal deformation on the brake pedal ‘feel’. The characteristics of the brake booster reaction disc were predicted by the FEA and AMESim simulation modelling and these results highlighted the importance of the nonlinear material characteristics, and their potential contribution to brake pedal ‘feel’ improvement. A full brake system simulation model was designed, prepared, and used to predict brake system performance and to design a system with better brake pedal ‘feel’. Each of the brake system component design parameters was validated to ensure that the braking system performance was accurately predicted. The critical parameter of brake booster air valve spring stiffness was identified to improve the brake ‘pedal ‘feel’. This research has contributed to the advancement of automotive engineering by providing a method for brake system engineers to design a braking system with improved pedal ‘feel’. The simulation model can be used in the future to provide an accurate prediction of brake system performance at the design stage thereby saving time and cost.

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